, An experiment started in the usual way lth cinbeitea and ” 
rise to a mixture of substances in which npenanee eee predamme 
not be pcaned, + 
Finally, Neuberg and Kerb report on some new crystalline derivatives ohm ; tre 
thiosemicarbazone, m.p. 200 to 201°; p-nitrophenylhydrazone, m.p. 125°. * | ’ 
Furthermore, we beg to report on a paper by Neuberg?) entitled, “7 general 
relation of the aldehydes to alcoholic fermentation, with remarks on- the: co- pico 
of yeast”. “oo Pc Neat A ea 
The auther points out that the enzyme « caroaiage? ‘containce in Lhe grouping of 
ferments comprised in the collective name of zymase, exerts a very high activity, since. 4 
it produces not alone the fermentative carbonic acid, but also aldehydes. The material : 
yielding the aldehydes are «-ketonic acids which, in the present view, are the primary — 
reaction-products in the animal and vegetable organism of the «-amino acids. Hence, Bs 
the carboxylase is one of the ferments serving to bring the degradation products — of 
albumen into reaction. The aldehydes which are ‘so widely distributed, although | in. 
minute quantities, may be considered as resulting from the action of the cathawiace ™ 
Quite recently, other relations of the system: carboxylase — «-ketonic acid to the 
important process of intramolecular respiration have been discovered, of which the 
example best known is the alcoholic fermentation. Neuberg and his collaborators 
have found that traces of «-ketonic acids of physiological importance activate the. 
process of sugar-fermentation in a marked degree. fa 
Neuberg was now able to demonstrate that the aldehydes count none the moses 
effective activators for alcoholic fermentation and in molecular respiration. With — 
38 aldehydes, aliphatic and aromatic, Neuberg proved the He action beyond 3 
doubt. i 
The aliphatic aldehydes, from formaldehyde to decylic aldehyde, gave a posited: 
reaction, equally so benzaldehyde and its homologues, the hydroxybenzaldehydes and 
their ethers of the anisic aldehyde and piperonal type, also phenylacetic aldehyde, — 
citronellal, citral, cyclocitral, and cinnamic aldehyde. The only exception was vanillin — 
(m- methoxy-p-hydroxy-benzaldehyde), where no activating effect could be. traced; in this. E 
case, however, the concentration may not have been the correct one. 
The activating power of the aldehydes manifests itself in the fermentation | 
d-glucose, d-fructose, and d-mannose, and their action comprises a very wide range | of — 
concentration, the same AeenyGe showing the same effect in dilutions differing bil 
1: 1000 (standard solution and suo standard solution). The active quantities may differ $ 
even in the ratio of 5000:1, as is shown by the activating power of 1.17 p.c. ¢ 
in the sugar solution and of the exceedingly low content of 0. ae pic: of formalde 
seteatass 
ts 9 
oe sae 
ee ee 
a 
1) Biochem. Zeitschr. 88 (1918), 145. 
